S空位调节扶手型二硫化钼纳米带的电子性质

Electronic properties of armchair MoS nanoribbons with S-vacancy regulation

二硫化钼纳米带按边界结构特征可分为锯齿型和扶手型,在制备过程中,不可避免地会存在一定的缺陷,其中硫空位(V_(S))最为常见,它将改变纳米结构,进而影响其电子性质.本文采用密度泛函理论来研究S空位对扶手型二硫化钼纳米带性质的影响.计算结果表明:纯扶手型二硫化钼纳米带(AMoS_(2)NRs)为非磁性半导体,但其物性受S空位的位置及浓度所调制.当S空位出现在纳米带内部时,其性质不变.但当S空位在纳米带边缘时,AMoS_(2)NRs被调节成半金属;并随着S空位的浓度的增加,其物性从半金属转变为稀磁半导体.这一有趣的发现将使得低维MoS2纳米材料在自旋电子学上有更宽广的应用.

Two-dimensional MoS_(2) can be tailored armchair MoS2 nanoribbons(AMoS2NR) and zigzag MoS2 nanoribbons(ZMoS_(2)NR) according to the edge structural feature. There are some defects in the preparation of MoS_(2) nanoribbons,among which sulfur(S) vacancies are the most typical. In this paper,the effect of S vacancies on the properties of AMoS2NRs is studied by density functional theory. The results show that the pure AMoS2NRs are the non-magnetic semiconductors,but their physical properties are modulated by the position and concentration of S vacancy. When S vacancies are on the edge,its property remains unchanged. However,when the S vacancies are at the edge of nanoribbons,the AMoS2NRs are adjusted into the semi-metals. And when the concentration of s vacancy increases,AMoS2NRs can be changed from semi-metals to diluted magnetic semiconductors.